/* libwatopt++ - Optimization Toolkit
 *
 * Copyright (c) 2007 Christopher Alexander Watford
 * <christopher.watford@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to
 * deal in the Software without restriction, including without limitation the
 * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
 * sell copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
 * IN THE SOFTWARE.
 *
 * $Id: utils.cpp 5 2007-05-12 19:19:02Z christopher.watford $
 */

#include <string>
#include <vector>
#include <map>
#include <ctime>
#include <iostream>

#include <utils.hpp>

namespace watopt
{

   static bool __utils_seeded = false;

   void
   seed_random(void)
   {
      if(!__utils_seeded)
      {
         std::srand((unsigned int)std::time(NULL));
         __utils_seeded = true;
      }
   }

   double
   rand01(void)
   {
      return (std::rand()/(1.0 + RAND_MAX));
   }

   size_t
   rand_index(size_t maxi)
   {
      return (size_t)(maxi * (std::rand() / (1.0 + RAND_MAX)));
   }

   template<typename T>
   void
   shuffle(T *arr, size_t count)
   {
      seed_random();

      assert(arr != NULL);

      for(size_t ii = 0U; ii < count; ii++)
      {
	      size_t kk = 0;
	      while((kk = rand_index(count)) == ii);

	      T temp = arr[kk];
	      arr[kk] = arr[ii];
	      arr[ii] = temp;
      }
   }

}
